Retractable roof



Nov. 26, 1968 RETRACTABLE ROOF Filed March 17, 1966 4 Shee ts-Sheet 1INVENTOR. NICHOLAS B. POP/L N. POPIL 3,412,509

Nov. 26, 1968 N. B. POPIL 3,412,509

RETRACTABLE ROOF Filed March 17, 1966 4 Sheets-Sheet 2 11v- VENTOR.lvluoL A8 a. POP/l.

NOV. 26, 1968 POPlL 3,412,509

RETRACTABLE ROOF Filed March 17, 1966 4 Sheets-Sheet 5 ,1 I II 80 I IIII I I INVENTOR. NICHOLAS a. POP/L Ii Q 78 BY I I f I H6. 7 a? QAMW/QYNov. 26, 1968 N. B. POPIL 3,412,509

RETRACTABLE ROOF Filed March 17, 1966 4 Sheets-Sheet 4 IN VENTOR.

NICHOLAS B. POP/L United States Patent 3,412,509 RETRACTABLE ROOFNicholas R. Pupil, 6945 W. Pleasant Valley Road, Cleveland, Ohio 44129Filed Mar. 17, 1966, Ser. No. 535,084 9 Claims. (Cl. 52-2) ABSTRACT OFTHE DISCLOSURE An overhead enclosure or cover for covering large areassuch as stadiums, arenas, factories, etc., which comprises a covermember connected to a top portion of the structure at the opening andmotive power means are connected to an opposite portion of the covermember for moving the cover back and forth across the opening to closethe same. Sealing means are provided for sealing the peripheral edge ofthe cover member to the top portion of the structure in a relativelyair-tight manner and means are provided for introducing air underpressure into the enclosure defined by the structure to extend the covermember preferably into a dome-like shape or into any other shapedepending upon the fabrication of the cover member.

The present invention relates in general to a roof construction and moreparticularly to a roof construction which can be utilized for thepurpose of covering large areas such as stadiums, arenas, or storage andmanufacturing areas, which roof can be moved from an open position wherethe area is exposed to the weather elements to a closed position whereinthe area is shielded from the weather elements.

As an example of the utility of the present invention one may take thecase of large sports arenas such as those presently utilized by themajor baseball leagues to play baseball and the major football leaguesin the playing of professional football. Most of these stadiums comprisevertically extending wall structure which rise to a given verticalheight which wall structure extends around and surrounds the playingfield and in a conventional manner includes seating for spectators. Theupper portion of the wall structure which extends around the playingfield usually terminates in what is commonly referred to as a roofthereon, however, the large area between the generally annularlyextending wall structure is exposed at all times to the weatherelements.

Provision has been made in some prior art structures to provide apermanent closure or roof over this hereinbefore uncovered area and thispermanent roof has included in some instances transparent portions inthe nature of glass or plastic members, however, this construction isgenerally of a permanent nature. Many disadvantages have arisen withthis type of structure such as glare from the sun resulting in playersof a sport being momentarily blinded by the sun. When the transparentclosures have been painted or otherwise treated to keep the sun out,difiiculties have been encountered in trying to keep the grass on theplaying field from dying.

The prior art has also utilized in some instances a roof structure forthis area which generally is of a permanent type construction but whichcan partially be uncovered by the rotation of various elements withrespect to each other in a generally angular direction.

The present invention seeks to obviate the disadvantages in any of thehereinabove described prior art structures by providing a roof orclosure member which can be readily opened and closed depending upon theWeather conditions exteriorly of the structure.

Another object of the present invention is to provide a coverconstruction for a stadium or other large uncov- 3,412,509 Patented Nov.26, 1968 ered area which utilizes a means for drawing the coveringbetween open and closed positions and sealing the cover member whenclosed, to the structure upon which it is mounted, and thereafter tocause air under pressure to be injected into the covered stadium toextend the cover member to a generally rounded or dome-like condition incovering the stadium.

Another object of the present invention is to provide a roof closureconstruction whereby the closure mechanism utilized includes cable meansfor drawing the cover member between open and closed position and alsowhere rails are provided for drawing the cover member between open andclosed positions.

Another object of the present invention is to provide a convenientmechanism for providing a seal at the periph eral edge of the covermember once the cover has been moved to a closed position with respectto the area it is to cover.

Another object of the present invention is to provide a mechanism forfolding the cover member when the cover member is moved to an openposition in uncovering an area.

Another object of the present invention is to provide a cover member forcovering a playing field or other large uncovered area which comprises ahigh strength plastic material which is translucent in nature and whichis formed in a shape so that when fully extended by the air pressureutilized therewith it will assume a generally domelike shape.

Other objects and a fuller understanding of this invention may be had byreferring to the following description and claims, taken in conjunctionwith the accompanying drawings, in which:

FIGURE 1 is an isometric view of the exterior of a stadium showing theroof closure of the present invention in a closed condition;

FIGURE 2 is an elevational view of the stadium shown in FIGURE 1;

FIGURE 3 is a plan view of FIGURE 2 and showing the cover member inretracted position;

FIGURE 4 is an enlarged view taken generally along the line 4-4 ofFIGURE 3 showing the fabric folding device;

FIGURE 5 is a view taken generally along the line 5-5 of FIGURE 4;

FIGURE 6 is an enlarged View of a portion of FIG- URE 4;

FIGURE 7 is an enlarged view taken generally along the line 7-7 ofFIGURE 3;

FIGURE 8 is an enlarged view taken generally along the line 88 of FIGURE3 showing the closing mechanism;

FIGURE 9 is a view taken along the line 99 of FIG- URE 8;

FIGURE 10 is a plan view of a stadium slightly different shaped than theone shown in FIGURES 1, 2 and 3 and illustrating a variation in themeans utilized to move the cover member between open and closedpositions;

FIGURE 11 is a somewhat diagrammatic representation of how the covermember shown in FIGURES 10 and 12 folds up as it is moved to openposition;

FIGURE 12 is an enlarged isometric view illustrating the tracks shown inFIGURE 10 which move the cover member between open and closed positions;

FIGURE 13 is a plan view of the cover member and showing the pattern ofreinforcing cables which extend therethrough to lend strength to theconstruction; and

FIGURE 14 is a view taken generally along the line 1414 of FIGURE 13.

As mentioned hereinabove, the present invention is susceptible of use inmany applications wherein it is desired to cover a relatively largearea. The embodiment illustrated in FIGURES 1, 2 and 3, to representsuch a large uncovered area, is a stadium 20. The stadium includes aplaying field 22 upon which many games can be played such as baseballand football. The stadium comprises a vertically extending wallstructure 24 which extends to a given height and which extends around inwhat may be referred to as an annular direction, the playing field. Inother words, the wall structure surrounds the playing field. The top ofthe vertically extending wall structure terminates in a fixed roof 26.As seen in FIGURE 3 the general pattern of the field assumes theconfiguration of an oval or might be said to be generally egg'shaped.The apparatus for covering the stadium or playing field includes aplurality of truss structures which are mounted on the fixed roof 26 andwhich extend all the way around the stadium roof. All of the trussstructures 29 are conventioual in nature being generally triangular inconfiguration and having an uppermost vertical apex or point. For thesake of more case in describing the details of the present invention thestadium 20 may be said to have first and second sides 31 and 32respectively and first and second ends 35 and 36 respectively. A firstsupport member 38 is fixedly connected to the apex of the trussstructures 29 on the first side 31 of the stadium and a second supportmember 40 is secured to the apex of the truss structure 29 on the secondside 32 of the stadium and these two support members will be describedin more detail hereinafter. Normally support member 38 would not be seenin FIGURE 3 because other structure would hide it from view but it hasbeen indicated so as to more quickly illustrate its general position. Athird support member 42 is secured to the apex of the truss structures29 on the first end 35 of the stadium and a fourth support member 44 issecured to the apex of the truss structures 29 at the second end 36 ofthe stadium.

A first plurality of pulley means 46 (FIGURE 4) are supported by giventruss structures 29 on the first side 31 of the stadium roof and asecond plurality of pulley means 48 are supported by given trussstructures 29 on the second side 32 of the stadium roof. For each of thepulley means on one side of the roof there is a corresponding pulleymeans on the other side of the roof. In the particular embodiment shownfor example in FIGURE 3, there has been shown five cables numbered 50through 54 and these cables are generally parallel with each other andextend across and over the playing field from the first to the secondside of the stadium roof and each cable is continuous in nature as seenin FIGURES 4 and 8 and extends around a pulley of the first and secondplurality.

A one-piece translucent plastic cover member 56 is provided and isconstructed and formed to assume generally the surface of a portion of asphere when fully extended. The particular construction of the covermember may be varied substantially, however, the fabric might beconstructed of nylon and/or Dacron covered with for example vinyl or aneoprene rubber. For the sake of example the cover member should have acomparatively high tensile strength preferably over 200 pounds persquare inch and should be as mentioned before, translucent. The materialshould have a low moisture absorption factor preferably less than 5% ofthe fabric weight and should comply with the cold snap test when used innorthern climates to 40 F. The construction should also includeanti-ozone compounds for protection from the ultra-violet rays of thesun and the material should be comparatively light weight, for exampleit should Weigh in the range of from 10 to 70 ounces per square yard.The material should be fire-resistant to meet Federal RegulationCCT-l9lB Method 5910. FIGURES 13 and 14 show some detail of the covermember. FIGURE 13 shows a plan view of the cover member which shows apattern of cables 57 extending therethrough. The cables extend through apiece of plastic pipe material 58 (FIGURE 4) which is held in positionby fabric pieces 61 held by a suitable adhesive.

The plastic cover member in any event has a peripheral edge whichgenerally assumes the configuration defined by the members 38, 40, 42and 44 as viewed in FIGURE 3. A portion 59 of the peripheral edge of thecover member is fixedly secured to the first support member 38 as seenin FIGURES 4 and 6 in a generally permanent and air-tight manner andmeans are provided for securing or connecting the opposite peripheraledge portion 60 of the cover member or that portion of the peripheral ofthe cover member which is to be connected with the second support member40 to each of the cables through 54. FIGURES 4 and 8 illustrate thismeans of connecting the second peripheral edge of the cover member toeach of the cables 50 through 54. This means includes a bracket 62fixedly secured to each of the cables 50 through 54. This means includesa bracket 62 fixedly secured to the cable at one portion and havinganother portion fixedly secured to the material of the cover member. Adrive motor 64 (FIG- URE 8) is provided for driving each of the cables50 through 54 and each of the drive motors is mounted by means of abracket 65 to a truss structure 29. As shown in FIGURE 8 the drive motordrives the pulley 48 of the second plurality by way of a belt 66,however, it will be readily appreciated that this drive might be a geardrive or other equivalent means. The drive motors 64 are all reversibleso as to drive the cables in both first and second directions back andforth across and above the playing field. The motors are alsosynchronized with respect to each other so as to drive their respectivecables at a speed which is proportionate to the complete distance thatmust be traversed so that the complete edge portion 60 arrives at thesecond side at the same time. Simply for the sake of example if Weassume that the cable 52 must span 500 feet and that the cable 50 mustspan 400 feet, in order to have the second peripheral edge 60 of thecover member carried by cable 52 arrive at the second side 32 at thesame time that the second peripheral edge of the cover member carried bycable 50 arrives at the second side 32, the cable 50 must be driven at alinear rate of speed which is four-fifths of the linear speed of cable52. In other words, the motors must be synchronized so that the secondperipheral edge of the cover member arrives at the first and secondsupport members 38 and 40 at the same time when the cover member istraveling between open and closed positions.

As mentioned hereinabove, the first peripheral edge portion 59 issecured to the first support member 38 in a fixed and relativelyair-tight manner. It is also necessary that the second peripheral edge60 of the cover member be sealed when it arrives at the second side 32of the roof member in contact with the second support member 40. Thiswill be best understood from referring to FIGURE 8 where it will be seenthat the bracket 62 carried by the cable 52 is formed at 68 (also seeFIGURE 4) so as to conform to the outer cylindrical contour of thesecond support member 40. Although they have not been shown, suitablelimit switches have been provided at both sides of the roof 26 to beengaged by either the cables or the bracket 62 so as to de-energize thedrive motors 64 when the cover member has traversed the given distance.When the cover member has moved to the position shown in FIGURE 8 theperipheral edge is fixedly secured to the support member 40 by means ofa sealing lever 70 which has a portion 71 which clampingly engages theperipheral edge of the cover member when a hydraulic piston and cylinderarrangement 72 is actuated. When actuated the sealing lever 70 is causedto pivot about its pivotal mounting 73 causing it to move from thedot-dash position 75 to the full line position whereat the peripheraledge of the cover member is sealed in contact with the support member40. When the piston and cylinder arrangement is deactuated the sealinglever is returned to the dot-dash position by means of a spring 76.

It is likewise necessary to seal the portion of the peripheral edge ofthe cover member which is located adjacent the support members 42 and44. This is accomplished by means of the structure which is illustratedin FIGURE 7. It will be seen that the cables 50 and 54 are locatedclosely adjacent the support members 42 and 44 and a portion of theperipheral edge of the cover member is reinforced and in its unsealedcondition travels in a position because of its weight slightly below thesupport members 42 and 44. When the second peripheral edge 60 hasarrived at the second support member 40 or in other words has traversedthe playing field, a pinion gear 78 is actuated by drive means not shownwhich services to drive a rack gear 79 which carries at its top asealing portion 80 which moves the peripheral edge of the cover memberinto contact with the support member 42 at the one end and a similarconstruction is used to move the other portion into sealing engagementwith the support member 44. In most instances it is desirable when thecover member has been moved to its closed condition to have a workman oroperator of the device check the peripheral edges of the cover memberadjacent the support members 40, 42 and 44 to assure that the peripheraledge will be properly located against its respective support memberbefore the sealing mechanisms are actuated.

It is also desirable to have mechanism for folding the cover member 56when the playing field is to be uncovered and the cover member is movedfrom the second side 32 of the stadium roof back to the first side 31.To accomplish this there is provided five folding mechanisms id :ntifiedby the reference numerals 82 through 86 (FIG- URE 3). Each of thefolding mechanisms is provided with a drive motor 88 which by way of apulley 89 drives four shafts upon each of which are mounted sheaves orpulleys 91 which in turn drives and contains fold cables 92 through 95.As will be seen from reviewing FIGURES 3 and 4, each of the fold cables92 through 95 of a given folding mechanism is attached to respectiveportions of the cover member at proportionate distances across theplaying field from the first to the second side thereof. In other words,referring to FIGURES 3 and 4, if one were to assume a span of 400 feetfor the cover member at cable 50, the fold cable 92 would be attached tothe cover member 80 feet from the first support member 38, the foldcable 93 would be attached 160 feet and so on in 80 foot intervals untilthe last fold cable 95 would be attached 80 feet from the secondperipheral edge 60 which would be located 320 feet away from the firstsupport member. In the folding mechanism 84 if one were to assume thespan of the field at this point to be 500 feet the fold cables would beattached to the cover member at 100 foot intervals.

In operation when the cover member is to be opened the drive motors 88are all actuated and these drive motors are synchronized so that theentire length of the second peripheral edge 60 of the cover member willarrive at the first side 31 of the stadium roof at the same time. Thedrive motors 64 are also synchronized with the drive motors 88 toaccomplish this desired end result. It will be seen that the foldingmechanism is contained in a covered enclosure defined by a wall 98 andeach of the cables 92 through 95 travel through an opening in this wall.As the cables 92 through 95 are Wound upon their respective pulleys itwill be seen that cable 92 where attached to the cover member willengage the wall 98 which prevents further winding of cable 92. This ispermitted because of a clutch construction between the shaft and thepulley for the fold cable 92 which enables the shaft to keep turningwithout further turning of the pulley. The next cable to be wound iscable 93, etc., through cable 95, with resultant folding of the covermember 56 as illustrated in FIG- URE 4. Either the main cables or thefold cables may have means attached thereto to de-energize both thedrive motors 88 and the drive motors 64 upon complete retraction of thecover member to the first side 31 of the stadium roof. When it isdesired to close the cover member the drive motors 64 perform thisfunction by way of cables 50-54 and the cables 92-95 associated withfolding mechanisms 82-86 are simply unwound from their respectivepulleys. The general position of the longest cables when the covermember is closed are shown in FIGURE 1.

The particular pattern or assemblage of the various pieces to make upthe entire cover member have not been illustrated in this particularembodiment however the as sembly is made by a series of separate piecessuitably connected together in a manner similar to that illustrated inFIGURE 14.

It is understood that the remainder of the stadium proper has previouslybeen rendered relatively air-tight by closing all apertures etc., andpersonnel or vehicles which are to enter or leave the stadium may passthrough an air lock which is in principle a double door or something onthe order of a rotating door so as not to lose pressure within theconfines ot the stadium.

Centrifugal blowers 111 are mounted on the stadium roof between thetruss structures and after the cover member has been moved to its closedposition and sealed, the centrifugal blowers are actuated to in effectinflate the cover member so as to hold it in the position shown inFIGURES 1 and 2. The inflation pressure under normal conditions wouldpreferably be on the order of about .25 pound per square inch, however,this pressure may be increased by the centrifugal blowers utilized, bymeans of suitable control mechanism which is not de scribed in anydetail herein. Safety valves 113 are also provided to insure that theair pressure does not exceed a predetermined level which condition couldarrive under certain conditions for example, by excessive warming orheating of the air contained in the closed stadium. If desired, prior toa game or immediately after one, the inflation pressure might bedispensed with resulting in the cover member in effect resting on thecables 50-54. This would expedite the entrance and exit of people fromthe structure which would be more time consuming if the air lock weremaintained. The cover member could again be inflated after the entranceor exit of the spectators.

FIGURES 10, l1 and 12 illustrate a modification of the structure whichis disclosed in FIGURES 1 through 9. In this embodiment a slightlydifferent shaped stadium 116 is disclosed which also extends around aplaying field and comprises vertically extending wall structureterminating at the top in a fixed roof 118. Positioned on the roof are aplurality of truss structures 119 and secured to the top of the trussstructures along each of two sides of the stadium roof are supportmembers 122 which take a cylindrical form and are preferably constructedfrom pipe. Also secured to the truss structures just outside the supportmembers are tracks 124 and 125 and a plurality of sliders 127 arepositioned on track 124 and a plurality of sliders 128 are positioned ontrack 125. A plurality of cables 129 extend between respective sliders127 and sliders 128 and each are secured to a cover member 131 which isof the same basic construction as the cover member 56 he'reinabovedescribed. The cover member at the end 134 of the stadium roof ispermanently anchored in position and the other end of the cover memberis adapted to travel back and forth to the other end 135 of the roofbetween open and closed positions. To accomplish this result there areprovided drive motors 136 and 137 located at the respective ends oftrack 124 and drive motors 138 and 139 are located at the respectiveends of track 125. A cable 140 extends through an opening in each of theplurality of sliders 127 and is connected at one end to a pulley drivenmotor 136 and at the other end is attached to a pulley driven by motor137. The cable 140 is attached only to the slider closest to drive motor137 and is freely slidable through the openings through which it extendsin each of the other sliders. It will thus be seen that as the drivemotors are actuated in a given direction, that since cable 140 isattached only to the slider adjacent drive motor 137, this willfacilitate movement of all of the sliders upon opening movement of thecover member or in a downward direction as viewed in FIGURE 10 since oneslider will engage the next and so on until the cover member has beenopened. In movng the cover member to closed position the reverse is truein that the slider which is attached to cable 140 serves to move all ofthe sliders to an extended position with respect to each other until thecover member is closed. This same construction is repeated with respectto sliders 128 on track 125 wherein a similar cable is driven by drivemotors 138 and 139 and is attached only to the slider adjacent drivemotor 139. FIGURE 11 is a representation of approximately how the covermember 131 folds as it is moved to an open position and the generalposition of the sliders.

After the cover member 131 has been moved to its closed position it isnecessary that .a substantially air tight seal be obtained between thesupport members 122 and the peripheral edge of the cover member. This isaccomplished with a mechanism such as that shown in FIGURE 12 and itwill be understood that it is necessary to seal the cover member alongits peripheral edge between each of the cables 129. However, since thismechanism is the same in all instances, only one has been shown. Inorder to accomplish this end result there has been provided a lever 142pivoted to the rail which is located adjacent at 143 and secured to theend of the lever 142 is an arcuately shaped sealing member 144 which isadapted to forceably hold the peripheral edge of the cover member to acorresponding portion of a support member. The lever 142 is movedbetween operative and inoperative positions by means of a hydraulicallyactuated piston and cylinder arrangement 145 which is connected by apivot 146 to the lever.

The cover member is also sealed along the ends 134 and 135 of thestadium roof in a like manner. However, at these ends one or twomechanisms covering the entire extent of this end might be utilizedsince it is not necessary to provide a seal between obstructing cables129.

Centrifugal blowers 150 are positioned on the stadium roof and areadapted to introduce air under pressure after the cover member has beenmoved to its closed and sealed position in a manner similar to thatdisclosed in the stadium described in conjunction with FIGURES 1 through9. Also not shown are suitable safety valves to assure that the pressurein the stadium does not rise above a predetermined value. Likewise as inthe previous stadium described it is also necessary that the remainderof the conventional stadium structure be rendered relatively air tightbefore .air pressure is introduced.

Obviously when it is desired to uncover the stadium it is necessary tomove the sealing levers 142 to inoperative position and actuate drivemotors 136 through 139 all of which are synchronized with each other soas to move the cables 140 pulling the extreme sliders located adjacentdrive motors 136 and 139 downwardly as viewed in FIG- URE 10 and as aresult moving the cover member to uncovered position with the covermember folding generally as shown in FIGURE 11.

It will thus be seen from reviewing the foregoing that the primaryobject of conveniently covering a large area such as a stadium has beenaccomplished in an economical and inventive manner.

It will be observed from FIGURE 2 that a guard 105 has been disposed onthe truss structures slightly below the top of the same for the purposeof preventing high winds from hitting the cover member at its connectionwith the support members. In this view the guard 105 has been shown onlyon the back side of the stadium so as not to interfere with theillustration of the other structure, but it will be understood that theguard extends completely around the stadium. This construction also isapplicable to the stadium shown in FIGURE 10.

Although this invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form has been made only by way of exampleand that numerous changes in the details of construction and thecombination and arrangement of parts may be resorted to 'withoutdeparting from the spirit and the scope of the invention as hereinafterclaimed.

What is claimed is:

1. A cover for an opening in an enclosure defined by wall meansincluding in combination a cover member, a first portion of said covermember being relatively permanently connected to a portion of the wallmeans at the opening in a relatively air tight manner, motive powermeans connected to a second portion of said cover member for moving samelaterally back and forth across the opening to open and close theopening, releasable sealing means for sealing said cover member to saidwall means around said opening in a relatively air tight manner in theclosed position of said cover member and for unsealing said cover memberso that it may be moved across said opening to open position, and meansfor introducing air under pressure into the enclosure to extend saidcover member in its closed position.

2. A cover as claimed in claim 1 wherein said cover member isconstructed of translucent plastic material and has a generallydome-like shape in extended position.

3. A cover as claimed in claim 1 wherein said motive power meanscomprises pulley means on opposed sides of the opening with cablesextending therebetween and a second portion of said cover member isconnected to said cables whereby said cover member is opened and closedin the direction of said cables when said cables are moved back andforth between said pulley means.

4. Apparatus for covering an open area defined by vertically extendingWall structure which extends at least partially around the open areaincluding in combination a first plurality of pulley members mounted onthe top portion of the wall structure at a first side thereof, a secondplurality of pulley members mounted on the top portion of the wallstructure at a second side thereof and being oppositely disposed withrespect to the pulley members of said first plurality, cable membersextending between respective pulley members of said first and secondplurality, a cover member having a first side portion fixedly secured tothe top portion of the wall structure at said first side thereof andhaving a second side portion secured to said cable members, drive meansfor moving said cable members to move said second side portion of saidcover member back and forth between said first and second side portionsof the wall structure to open and closed positions respectively, sealingmeans for sealing said cover member around its peripheral edge portionto the top portion of the wall structure in a relatively air tightmanner, said sealing means comprising first and second members, meansfor moving said members relative to each other to entrap said peripheraledge portion in said closed position of said cover member and to releasesaid peripheral edge portion whereby said drive means may move saidcover member to said open position, and means for introducing air underpressure into the open area after said second side portion of said covermember has been moved closed to said second side portion of the wallstructure and said first and second members having entrapped saidperipheral edge portion of said cover member.

5. Apparatus as claimed in claim 4 wherein said cover member isconstructed of translucent plastic material and has a generallydome-like shape when extended by the introduction of air under pressureinto the open area.

6. Apparatus as claimed in claim 4 wherein folding means are located atsaid first side portion of said wall structure to fold said cover memberwhen same is moved to an open condition, said folding means arrangingincrements of said cover member generally horizontally and in avertically extending stack.

7. Apparatus for covering an open area defined by vertically extendingwall structure which extends at least partially around the open areaincluding in combination, first and second tracks mounted on the topportion of the wall structure at first and second sides thereofrespectively, a plurality of slide members mounted on each of said firstand second tracks, a cover member, 'a plurality of cables extendingbetween corresponding slide members on said first and second tracks andeach being connected to said cover member, means fixedly securing oneend of said cover member to the top portion of the wall structurebetween a first end of said tracks, drive means for moving said slidemembers back and forth on said tracks between said first end thereof anda second end thereof to open and closed positions respectively, meansfor sealing said cover member to the wall structure along said first andsecond sides and at said second end, said sealing means comprising firstand second members, means for moving said members relative to each otherto entrap said sides and said second end of said cover member in saidclosed position of said cover memher and to release said sides and saidsecond end of said cover member whereby said drive means may move saidcover member to said open position, and means for introducing air underpressure into said open area when said cover member has been closed andsaid first and second members have entrapped said sides and said secondend of said cover member.

8. Apparatus as claimed in claim 7 wherein said cover member isconstructed of translucent plastic material.

9. Apparatus as claimed in claim 7 wherein said cover member has agenerally dome-like shape when extended by the introduction of air underpressure into the open area.

References Cited UNITED STATES PATENTS 2,754,899 7/ 1956 Karobonink160-23 2,898,607 8/ 1959 McGuire 160-23 2,958,083 11/ 1960 Shook 160-263,050,743 8/ 1962 Lamb 160-310 3,051,232 8/1962 Lamb 160-273 3,277,61510/ 1966 Marquez 52-2 REINALDO P. MACHADO, Primary Examiner.

